Governments regulate chlorine levels in water to keep it safe for consumers to drink

Chlorine has long been used to disinfect water and make it safe to drink, but some social media users are claiming chlorine’s presence in water is cause for concern.

A TikTok video shared Feb. 26 on Facebook shows a clip from a 2018 broadcast by KGUN-TV in Tucson, Arizona, in which an employee of H2O Concepts, a company that sells water filtration systems, claims that unfiltered tap water is dangerous because of "contaminants, like chlorine."

"Chlorine is a poison. That’s why they put it (in tap water), to kill the bacteria that would grow in our water. Chlorine has been linked to high blood pressure, heart disease, Alzheimer’s and cancer," Derk Chamberlin of H2O Concepts claimed in the video.

Chamberlin claimed that tap water is not only unsafe to drink, but also shouldn’t be used for bathing or showering because "our bodies absorb all the contaminants, like chlorine, six times faster than we can drink it."

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook and Instagram.)

KGUN-TV, the Tucson news outlet, has broadcast several segments sponsored by H2O Concepts that repeat similar claims about the dangers of chlorine in tap water. In these segments, H2O Concepts’ water filtration systems are promoted as a solution.

Water from lakes and wells, if left untreated, can be contaminated with bacteria and cause diseases such as salmonella and norovirus. Most communities in the United States use chlorine or chloramine to disinfect their water supplies and protect against these diseases.

Chlorine was first used in the U.S. as a major water disinfectant in 1908 in Jersey City, New Jersey. In the following decades, it became more widely adopted. And now, chlorine is one of the most commonly used water treatment chemicals in the country.

Federal and state authorities regulate the use of chlorine as a disinfectant. The U.S. Environmental Protection Agency sets legal limits for more than 90 contaminants, including chlorine, in drinking water.

The maximum amount of chlorine allowed in tap water is 4 milligrams per liter, per EPA regulations. At this low level, harmful health effects are unlikely to occur, according to the EPA and the Centers for Disease Control and Prevention.

Although chlorine is toxic to fish, reptiles and amphibians, the chemical is not directly absorbed into the human bloodstream, according to the CDC.

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Prolonged human exposure to chlorine above the legal limit could lead to eye and nose irritation and stomach discomfort, the EPA said.

Chlorine has not been classified as a carcinogen (a substance that causes cancer), according to the CDC.

A TikTok video shared on Facebook claimed that chlorine’s presence in tap water is dangerous.

For more than 100 years, chlorine has been used to disinfect water supplies and protect against diseases. Federal and state governments regulate the levels of chlorine in drinking water, so only a trace amount of the chemical is allowed.

This low level of chlorine is unlikely to cause any harmful health effects, the EPA and CDC said.

We rate this claim False.